1. Field of the Invention
The present invention relates to a hash algorithm apparatus and an encryption apparatus using the same, and more particularly, to a low power SHA-1 hash algorithm apparatus having an optimized low power structure of a keyed-hash message authentication code (HMAC) algorithm used to a platform related to an integrity verification on a platform and user authentication in a mobile device having a limited power resource such as a mobile trusted computing environment, such as a mobile phone and a personal digital assistant or an embedded system requiring low power consumption, and a low power HMAC encryption apparatus using the low power SHA-1 hash algorithm apparatus.
The present invention has been partly supported by the IT R&D program of MIC/IITA [2006-S-041-02, titled: Development of a Common Security Core Module for Supporting Secure and Trusted Service in the Next Generation Mobile Terminals].
2. Description of the Related Art
Recently, together with rapid development of wireless network technology, as it becomes a high degree of a digital information-oriented society and electronic commercial transactions are activated, encryption technology is considered as core technology for stability and reliability of social, economic activities and protecting privacy of a user based on high speed Internet networks. Particularly, a mobile platform such as a mobile phone may be an object of an attack from a hacker or other harmful programs if there is no suitable security management.
On the other hand, trusted computing group (TCG) is a group developing and promoting open specification on a security solution for various computing systems. Recently, TCG published several documents and standards defining the execution of various applications for stable processes related to booting a system, an administration of an environment of a platform, and a personal computing platform. An essential element of TCG standards is trusted platform module (TPM) monitoring a platform and reporting a state thereof.
The TPM may provide stable encryption key storage function together with public key encryption operation, signature, and the faculty of a hash function, as a separate trusted coprocessor. Also, internal state thereof is incapable of being arbitrarily operated by software of a host system. By using the security function of the TPM, a user may assure an initial environment of a platform or may seal or bind data to a certain environment of platform.
Particularly, mobile phone working group (MPWG) of the TCG extends security standards to be suitable for a mobile phone device. In the security standards, to estimate integrity of a platform and verify the integrity, a mobile trusted module (MTM) that is an essential security module for a mobile phone device designates that secure hash algorithm-1 (SHA-1) hash function using no key is used together with a keyed-hash message authentication code (HMAC) algorithm using a key.
The HMAC is an encryption method of generating a message authentication code (MAC) by using a hash function. Generally, a hash function is a function compressing a bit stream with a certain length into a hash code that is an output value with a fixed length. As a representative hash function, there is SHA-1 obtained by modifying/complementing SHA in 1995, the SHA was designed by national security agency (NSA) in 1993. The SHA-1 receives input data with a certain length, make input data 512 bit unit by using separating a message or using 0 padding, and performs round operation processes of 80 times, thereby obtaining an output of 160 bits and having resistibility against most of attacks.
However, there is a limitation on a memory and available power source and computing ability of most mobile devices or embedded systems, there are various technical difficulties to apply the security standards of the TCG to mobile phones. Particularly, in the case of mobile phones, since there is a limitation on a capacitance of a battery thereof, there is a great limitation on power consumption among such limitations. Accordingly, it is required to design a small low power SHA-1 circuit and an HMAC circuit.